Abstract: A directional coupler circuit includes a signal line disposed between a first terminal and a second terminal; a coupling line comprising a first end terminal and a second end terminal, and disposed to be coupled to the signal line; a switching circuit connecting the first end terminal and a coupling port to each other to extract a first coupling signal in a first coupling mode, and connecting the second end terminal and the coupling port to extract a second coupling signal in a second coupling mode; and a phase compensating circuit configured to compensate for a phase difference between the coupling port and a first isolation port in the first coupling mode, or compensate for a phase difference between the coupling port and a second isolation port in the second coupling mode.

Abstract: An amplifying device includes: an amplifying circuit connected between an input terminal and an output terminal and amplifying a signal input in an amplification mode; and a bypass circuit including a filter connected to a bypass path for bypassing the amplifying circuit, wherein the bypass path is in an off-state in the amplification mode and is in an on-state in a bypass mode, and the filter bypasses an input high-frequency signal to ground, in the amplification mode.

Abstract: A radio frequency switching device includes a switching circuit including first and second transistors; a gate resistor circuit including a first gate resistor and a second gate resistor, the first gate resistor connected to a gate of the first transistor and the second gate resistor connected to a gate of the second transistor; a gate buffer circuit including a first gate buffer and a second gate buffer, the first gate buffer being connected to the first gate resistor to provide a first gate signal to the first transistor through the first gate resistor, the second gate buffer being connected to the second gate resistor to provide a second gate signal to the second transistor through the second gate resistor; and a delay circuit to generate the first gate signal having a first switching time and the second gate signal having a second switching time different than the first switching time.

Abstract: A radio frequency switch circuit is described including a radio frequency switch and a coupler. The radio frequency switch includes a first band switch circuit connected between a first signal port and a common port, and configured to switch a first band signal. The coupler includes a first coupling wiring, disposed adjacent to a signal wiring formed between the common port of the radio frequency switch and an antenna port, and configured to form a first coupling signal with the signal wiring. A resonant frequency of the first coupling wiring is based on an inductance of the first coupling wiring and a capacitance of the radio frequency switch.

Abstract: An amplifying apparatus includes a variable gain amplifying circuit configured to operate in a gain mode selected from a plurality of gain modes in response to a first control signal during operation in an amplification mode, a variable attenuation circuit configured to have an attenuation value that is adjusted in response to a second control signal, and a phase compensation value which compensates for a phase distortion in the selected gain mode, and a control circuit configured to control the selecting of the gain mode, the adjusting of the attenuation value and the phase compensation value, based on the first and second control signals.

Abstract: A coupler circuit includes: a signal line disposed between a first terminal and a second terminal; a coupling line disposed between a coupling port and an isolation port such that the coupling line is coupled to the signal line and is configured to extract a coupling signal from the signal line; and a coupling adjusting circuit connected to the coupling port and the isolation port, and configured to reduce changes in an amount of coupling according to a change in a frequency band of a signal passing through the signal line.

Abstract: An apparatus includes an amplifying circuit configured to include stacked first and second transistors, and to amplify a signal input from an input terminal during an operation in an amplifying mode, and provide the amplified signal to an output terminal, and a negative feedback circuit comprising first to nth sub-negative feedback circuits, each corresponding to a separate gain mode included in the amplifying mode, wherein the negative feedback circuit is configured to provide a variable resistance value to determine a negative feedback gain based on each of the separate gain modes.

Abstract: A low noise amplifier circuit includes a first low noise amplifier including a common gate structure cascoded with a parallel common source structure to selectively amplify a band signal among first and second band signals; a second low noise amplifier including a common gate structure cascoded with a parallel common source structure to selectively amplify a band signal among third and fourth band signals; an output DPDT circuit including a first input terminal connected to the first low noise amplifier, a second input terminal connected to the second low noise amplifier, and a first output terminal and a second output terminal for selectively outputting signals input through the first input terminal and the second input terminal; and a control circuit performing an amplification control and a switching control for the first and second low noise amplifiers and the output DPDT circuit in response to a predetermined communications scheme.

Abstract: A radio frequency switching device includes a switching circuit including first and second transistors; a gate resistor circuit including a first gate resistor and a second gate resistor, the first gate resistor connected to a gate of the first transistor and the second gate resistor connected to a gate of the second transistor; a gate buffer circuit including a first gate buffer and a second gate buffer, the first gate buffer being connected to the first gate resistor to provide a first gate signal to the first transistor through the first gate resistor, the second gate buffer being connected to the second gate resistor to provide a second gate signal to the second transistor through the second gate resistor; and a delay circuit to generate the first gate signal having a first switching time and the second gate signal having a second switching time different than the first switching time.

Abstract: A radio frequency switch circuit includes: a radio frequency switch configured to control a radio frequency signal passing between a signal port and an antenna port; a first buffer configured to generate the first control voltage in response to a second control voltage; a second buffer configured to receive a third control voltage and configured to generate the second control voltage in response to the third control voltage; a first power supplier configured to supply a first high voltage to the first buffer and configured to supply a second high voltage to the second buffer; and a second power supplier configured to supply a first low voltage to the first buffer and configured to supply a second low voltage to the second buffer.

Abstract: A voltage dropping apparatus may include: a voltage dropping unit receiving an input voltage, outputting the input voltage in a first mode, and dropping a level of the input voltage in a second mode; a voltage output unit connected to the voltage dropping unit, receiving and outputting the input voltage in the first mode, and receiving and outputting the dropped voltage in the second mode; and a control unit receiving a mode signal and controlling a mode change of the voltage dropping unit and the voltage output unit based on a value of the mode signal.

Abstract: A radio frequency switch circuit is described including a radio frequency switch and a coupler. The radio frequency switch includes a first band switch circuit connected between a first signal port and a common port, and configured to switch a first band signal. The coupler includes a first coupling wiring, disposed adjacent to a signal wiring formed between the common port of the radio frequency switch and an antenna port, and configured to form a first coupling signal with the signal wiring. A resonant frequency of the first coupling wiring is based on an inductance of the first coupling wiring and a capacitance of the radio frequency switch.

Abstract: An antenna switch circuit includes: a first switch circuit connected between a first signal port for signal transmission and reception and an antenna port, and operated by a first gate signal; and a second switch circuit connected between a second signal port for signal transmission and reception and the antenna port, and operated by a second gate signal. The first switch circuit and/or the second switch circuit includes a first transistor and a second transistor connected in series between the first and second signal ports, a first voltage dividing circuit including a first resistor and a second resistor connected in series between a source and a drain of the first transistor, and a first variable capacitor circuit connected between the first voltage dividing circuit and a body of the first transistor, and having capacitance varying according to a voltage across opposite ends of the first variable capacitor circuit.

Abstract: A radio frequency switch circuit is described including a radio frequency switch and a coupler. The radio frequency switch includes a first band switch circuit connected between a first signal port and a common port, and configured to switch a first band signal. The coupler includes a first coupling wiring, disposed adjacent to a signal wiring formed between the common port of the radio frequency switch and an antenna port, and configured to form a first coupling signal with the signal wiring. A resonant frequency of the first coupling wiring is based on an inductance of the first coupling wiring and a capacitance of the radio frequency switch.

Abstract: A radio frequency switch circuit includes: a radio frequency switch configured to control a radio frequency signal passing between a signal port and an antenna port; a first buffer configured to generate the first control voltage in response to a second control voltage; a second buffer configured to receive a third control voltage and configured to generate the second control voltage in response to the third control voltage; a first power supplier configured to supply a first high voltage to the first buffer and configured to supply a second high voltage to the second buffer; and a second power supplier configured to supply a first low voltage to the first buffer and configured to supply a second low voltage to the second buffer.

Abstract: An antenna switch circuit includes: a first switch circuit connected between a first signal port for signal transmission and reception and an antenna port, and operated by a first gate signal; and a second switch circuit connected between a second signal port for signal transmission and reception and the antenna port, and operated by a second gate signal. The first switch circuit and/or the second switch circuit includes a first transistor and a second transistor connected in series between the first and second signal ports, a first voltage dividing circuit including a first resistor and a second resistor connected in series between a source and a drain of the first transistor, and a first variable capacitor circuit connected between the first voltage dividing circuit and a body of the first transistor, and having capacitance varying according to a voltage across opposite ends of the first variable capacitor circuit.

Abstract: A voltage dropping apparatus may include: a voltage dropping unit receiving an input voltage, outputting the input voltage in a first mode, and dropping a level of the input voltage in a second mode; a voltage output unit connected to the voltage dropping unit, receiving and outputting the input voltage in the first mode, and receiving and outputting the dropped voltage in the second mode; and a control unit receiving a mode signal and controlling a mode change of the voltage dropping unit and the voltage output unit based on a value of the mode signal.

Abstract: A radio frequency switch circuit, according to examples, includes a switching circuit controlled to be in a turned on or turned off state on the basis of a gate signal to thereby allow a radio frequency signal to pass or be blocked; a voltage dividing circuit connected to terminals of the switching circuit that the radio frequency signal passes through and outputting intermediate voltage between the terminals by a voltage dividing node; and an impedance circuit connected between the voltage dividing node and a body terminal of the switching circuit.

Abstract: A radio frequency switch circuit is described including a radio frequency switch and a coupler. The radio frequency switch includes a first band switch circuit connected between a first signal port and a common port, and configured to switch a first band signal. The coupler includes a first coupling wiring, disposed adjacent to a signal wiring formed between the common port of the radio frequency switch and an antenna port, and configured to form a first coupling signal with the signal wiring. A resonant frequency of the first coupling wiring is based on an inductance of the first coupling wiring and a capacitance of the radio frequency switch.

Abstract: A voltage dropping apparatus may include: a voltage dropping unit receiving an input voltage, outputting the input voltage in a first mode, and dropping a level of the input voltage in a second mode; a voltage output unit connected to the voltage dropping unit, receiving and outputting the input voltage in the first mode, and receiving and outputting the dropped voltage in the second mode; and a control unit receiving a mode signal and controlling a mode change of the voltage dropping unit and the voltage output unit based on a value of the mode signal.